Protective helmet



FIG. 1 is a right frontal perspective view of a protective helmetshowing my new design, the visor being in a lowered position;

FIG. 2 is a right rearward perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a front view with the visor in a raised position;

FIG. 6 is a right side view with the visor in a raised position;

FIG. 7 is a right side view with the visor on a lowered position;

FIG. 8 is a left side view with the visor in a lowered position; and,

FIG. 9 is a left rearward perspective view with the visor in a loweredposition.

I claim the ornamental design for a protective helmet, substantially asshown and described.